DSM-II was published in 1968. DSM-5 will be published in 2013. How much progress have we made? I propose that we approach this question with a quiz.

My criterion of progress will be your ability to distinguish definitions and criteria from one DSM to the next. If the subsequent edition of the manual represents progress over its predecessor, that should be evident in the DSM text. If, on the other hand, you can’t distinguish an earlier from a later edition, we can question what has been accomplished with all the work of revision.

Let’s try this for the king of disorders, schizophrenia. We’ll start with definitions in DSM-II, -III, and -IV, as we don’t have definitions posted on the Web site for DSM-5.

Item #1. Your first challenge is the definition of schizophrenia, disorganized type (called hebephrenia in DSM-II but renamed disorganized for purposes of the quiz). Here are the three definitions from DSM-II, -III, and -IV. Match the definition to the manual.

Schizophrenia, disorganized type

(1) The essential features of this type are incoherence, marked loosening of associations, or grossly disorganized behavior, and, in addition, flat or grossly inappropriate affect. There are no systematized delusions, …although fragmentary delusions or hallucinations, in which the content is not organized into a coherent theme, are common.

(2) This psychosis is characterized by disorganized thinking, shallow and inappropriate affect, unpredictable giggling, silly and regressive behavior and mannerisms, and frequent hypochondriacal complaints. Delusions and hallucinations, if present, are transient and not well organized.

(3) The essential features of the disorganized type of schizophrenia are disorganized speech, disorganized behavior, and flat or inappropriate affect. The disorganized speech may be accompanied by silliness and laughter that are not clearly related to the content of the speech.

Item #2. The second item in the quiz is definition of schizophrenia, paranoid type. Here are the three definitions. Again, match the definition to the manual.

Schizophrenia, paranoid type

(1) The essential feature of this type of schizophrenia is preoccupation with one or more systematized delusions or frequent auditory hallucinations related to a single theme. In addition, symptoms characterized of the disorganized or catatonic types, such as incoherence, flat or grossly inappropriate affect, catatonic behavior, or grossly disorganized behavior, are absent.

(2) The essential feature of the paranoid type of schizophrenia is the presence of prominent delusions or auditory hallucinations in the context of a relative preservation of cognitive functioning and affect. Symptoms characteristic of the disorganized and catatonic types (eg, disorganized speech, flat or inappropriate affect, catatonic or disorganized behavior) are not prominent. Delusions are typically persecutory or grandiose, or both, but delusions with other themes (eg, jealousy, religiosity, or somatization) may also occur. The delusions may be multiple, but are usually organized around a coherent theme.

(3) This type of schizophrenia is characterized primarily by the presence of persecutory or grandiose delusions, often associated with hallucinations. Excessive religiosity is sometimes seen. The patient’s attitude is frequently hostile and aggressive, and his behavior tends to be consistent with the delusions.

Item #3. To bring DSM-5 into the quiz we have to move from definitions to diagnostic criteria, which are included in the online DSM-5 Web site. For this question we leave out DSM-II, which does not have diagnostic criteria. Your challenge now is to distinguish DSM-III, IV, & 5.

The third item of the quiz is Criterion A for schizophrenia. Match the criteria set to the manual.

Schizophrenia Criteria A

(1) A. Characteristic symptoms: Two (or more) of the following, each present for a significant portion of time during a 1-month period (or less if successfully treated): (a) Delusions (b)Hallucinations (c) Disorganized speech (eg, frequent derailment or incoherence) (d) Grossly disorganized or catatonic behavior (e) Negative symptoms, ie, affective flattening, alogia, or avolitionNote: Only one Criterion A symptom is required if delusions are bizarre or hallucinations consist of a voice keeping up a running commentary on the person's behavior or thoughts, or two or more voices conversing with each other.

(2) A. Presence of characteristic psychotic symptoms in the active phase: either (1), (2), or (3) for at least one week (unless the symptoms are successfully treated:

(I) Two of the following: (a) Delusions (b) Prominent hallucinations (throughout the day for several days or several times a week for several weeks, each hallucinatory experience not being limited to a few moments) (c) Incoherence or marked loosening of associations (d) Catatonic behavior (e) Flat or grossly inappropriate affect

(II) Bizarre delusions, ie, involving a phenomenon that the person’s culture would regard as totally implausible (eg, thought broadcasting, being controlled by a dead person).

(III) Prominent hallucinations [as defined in (1)(b) above] of a voice with content having no apparent relation to depression or elation, or a voice keeping up a running commentary on the person’s behavior or thoughts, or two or more voices conversing with each other.

(3) A. Characteristic symptoms: Two (or more) of the following, each present for a significant portion of time during a 1-month period (or less if successfully treated). At least one of these should include 1-3: (a) Delusions (b) Hallucinations (c) Disorganized speech (d) Grossly abnormal psychomotor behavior, such as catatonia (e) Negative symptoms, ie, restricted affect or avolition/asociality

ConclusionSo what has this quiz demonstrated? Assuming that you did not get a perfect score (or perhaps even if you’re really clever and did), the quiz suggests that a lot of work goes into changes that are both trivial and not distinguishable by the superiority of one to the other. A cynic might add that if you’re going to publish a new manual, you had better not just copy the last one.

But someone will object that I have cherry-picked the trivial and ignored the essential. After all, we were overdiagnosing schizophrenia in the 1960s and 1970s, and DSM-II did not stop that. In their landmark article on diagnostic validity, Robins and Guze1 focused on distinguishing real schizophrenia from what were probably affective psychoses; and in 1980 DSM-III introduced the criterion of six months of continuous illness for a diagnosis of schizophrenia. The six-month criterion was a watershed that remained in all succeeding DSMs. The question provoked by the quiz, however, remains: whether other changes in the schizophrenia section from manual to manual have been mostly window dressing.